Tint, Binning, and CRI Explained (For XM-L LEDs)

I doubt one could do it without losing even more light.

Just found an explanation on wikipedia.
"For example, the efficiency of a typical...yellow phosphor based white LED ranges from 3 to 5 times the efficiency of the original blue LED because of the greater luminous efficacy of yellow compared to blue light."
http://en.wikipedia.org/wiki/Light-emitting_diode#Phosphor-based_LEDs
Basically, human eyes are much more sensitive to white (or yellow) light which is the cause of all this.
http://en.wikipedia.org/wiki/Luminosity_function
The blue light produced is at 450 nm while the white light (after going through the phosphor) is around 575-600. So if you look at the graph, the human eye is very sensitive to white light, but not the blue light.
So now I understand it. :D

I do too, but its already in the one stop mod reference shop, so easy to find. :wink:

Excellent resource. Now if you could do one on the meaning of “XM-L” vs “XP-G” etc. It would be neat to know more behind the naming and designation of each.

What do you mean? The number of bond wires, size, efficiency, etc? Maybe if I get a chance I'll do that but this one was prompted by a few people PMing me in the past about tint, along with Nitro's question about where to get a neutral LED.

What surprises me is I was able to do 90% of this with out having to look anything up, I guess that's what happens when I spend so much time here.

I’m beginning to worry about how much I soak up on something I take an interest in, six months ago, I didn’t know what an xm-l was….know I’m growing bored of them…not bored as in not using them, just want to play with other things, I’m going backwards though, starting playing with xp-g’s etc. Bothering about modes and tint more than total output.

Sometimes a q5 in a suitable host with a good 1.4a driver is more usefull than an over driven xm-l lumen monster.

I’m a heretic, stone me :*

Ok, a comparison LED post is in the works.

I think I’m in the same boat as you. I have drawers full of lumens and sheer output isn’t a real big deal to me any more. I’m now more drawn to different tints and their visual relation with different beam profiles. If I see a flashlight with a choice of an XP-G 4C - 450Lm or an XM-L U2 - 800Lm, I will probably go with the XP-G 4C.

…And thanks so much Scaru. I hope you don’t mind that I copied and pasted your post right into my Evernote flashlight file.

Ouchyfoot, I don't mind in the least and am happy to be able to contribute back to the forum in this way. :)

I noticed you don’t have any links for 4C tints, which is my favorite right now, although I have yet to try a 5C.

The bad thing is, I should get a p60 host, build many pills, then its half scientific. That’s not going to happen though, I just don’t like p60’s so common sense is out the window…

WOW! Great info Scaru!!! THANKS!!! That is the best I have ever seen the information laid out!!!

Dan.

Not quite. CW XML typical CRI is 65. Typical CRI for CW XPE, XPG, XRE, Rebel, and most other current gen 3.45mm square emitters is between 70 and 75. Typical CRI for NW and WW emitters depends a lot on the specific model of emitter. For NW, it ranges from 70 to 80 depending on the type of emitter (not including "high CRI" emitters), and for WW, it ranges from 75-85 (also not including "high CRI" emitters).

Nice thread along with your other comparison thread.

Question - XM-L led's include a high CRI bin. I dont see this or anything about it..Sure, its for sale somewhere. I think its an S2 bin although i may be wrong in regards to the bin

Yes, to find that type of LED you need the model number. This is listed in the datasheet. Then simply take the model number and google it. (In this case:
XMLAWT-00-0000-000US60E7)
Then you come up with the Mouser link.
http://ca.mouser.com/ProductDetail/Cree-Inc/XMLAWT-00-0000-000US60E7/?qs=sGAEpiMZZMvmVP6pKcvh1c7ty4GjCwvt
I think I have responded to all of the questions/comments/errors in my post. If I missed any or you find any more just tell me.

Lots of info and nicely explained. I will probably have to come back to it later after I can wrap my head around all this a little bit better.

good point! I’ve spent most of my time poring over XM-L datasheets and I’m much less familiar with the other types :slight_smile:

Thank you scaru.

I am a newbie and have been reading this forum for a while trying to get myself educated. Your work on the XM-L LEDs has been most helpful for my to get a little better understanding of some of the technical aspects of these magic flashlights that I am so intrigued with.

I have purchased a few different lights and am now at the point where I want to build my first one. With this info I will be able to settle on at least one element of the new build.

Glad I could help! If you have any other questions just post! :)